Two formalisms used in index profile reconstructions are compared. We develop a novel formulation of the WKB inverse method and show that this method is not sufficient to recover the entire index profile in ion-implanted waveguides. A reflectivity calculation involving a matrix formalism solves the problem. The index profile parameters are adjusted to fit experimental mode indices. With this formalism, the reconstruction of the entire index profile is achieved. An application is shown in a BaTiO<sub>3</sub> sample.
© 1995 Optical Society of America
P. Mathey, P. Jullien, and J. L. Bolzinger, "Refractive-index profile reconstructions in planar waveguides by the WKB inverse method and reflectivity calculations," J. Opt. Soc. Am. B 12, 1663-1670 (1995)